#include <bits/stdc++.h>
#include <stdio.h>

using namespace std;

#define DEB(x) cout << #x << " = " << x << endl;

int nums[200001];

int main(void) {

    int n;
    while (scanf("%d", &n) == 1) {
        for (int i = 1; i <= n; i++) {
            scanf("%d", &nums[i]);
        }

        int swaps = 0;
        bool change = true;
        while (change) {
            change = false;
            for (int i = 1; i <= n; i++) {
                if (nums[i] != i) {
                    swap(nums[i], nums[nums[i]]);
                    swaps++;
                    change = true;
                }
            }
        }

        printf("%d\n", swaps);
    }

    return 0;
}